1. Field:
The invention is in the field of insulation for building or other purposes.
2. State of the Art:
With the cost of energy continuing to rise, people have become energy conscious. As part of this energy consciousness, there has been a continuing search for improved insulating materials to be used particularly in building to reduce heat loss from or heat entry into buildings and homes. The most common insulating materials are fiberglass batting, expanded plastic foam and cellulose insulation made from newspapers and cardboard. U.S. Pat. No. 2,039,601 shows building panels having sealed air compartments therein that act as insulation.
Vacuum has been known as an insulator, but has not been used in building materials. Since vacuum must be held in a chamber, and such chamber must be relatively strong, the use of vacuum as insulation has been limited to small containers such as thermos bottles. U.S. Pat. No. 3,150,793 shows a tank structure made up of insulating sections having vacuum therein while U.S. Pat. No. 3,769,770 shows a super insulating material made up of tiny spheres maintained in a vacuum and describes also another super insulating product made up of foil layers and fibrous material maintained in a vacuum. Such insulation may have as many as 75 layers per inch. These materials, however, are used only in special high heat applications and are not generally available or economical enough for use as building insulation.